建设项目工程承包合同计价采用（）方式，工程发包人要承担物价上涨带来的风险。

A.可调总价合同

B.固定总价合同

C.单价合同

D.成本加酬金合同

—Can we fix a time for the party?

—We can’t have the party________none of us have any classes.

A．except

B．except for

C．except when

D．except that